A high resolution agarose gel electrophoretic test for the determination of serum lipoproteins has been applied in the study of selected groups of patients of NIH protocols. In one study an abnormal pre-beta lipoprotein was detected in the serum of patients with systemic mastocytosis known to develop advanced atherosclerosis. In another study abnormal lipoprotein patterns were found in serum of growth hormone deficient children after growth hormone administration.